The present invention relates generally to a printer with a paper feeding mechanism and more particularly to a printer with a print head and a paper guide path.
The prior art printer of this kind is provided with a semi-circular paper guide path extending around the circumference of the cylindrical platen from the rear of the platen to the printing position on the front surface of the platen. A paper feeding device is located behind the platen so as to feed sheets of paper one after another automatically into the paper guide path, and an insert slit is formed between the paper feeding device and the platen so that a piece of paper is manually inserted from the insert slit. A paper tray is disposed near the paper discharging portion so as to receive the individual cut printed sheets one after another. Furthermore, a pin tractor unit is located below the paper feeding device so that a continuous web with pin feed holes on both outer edges thereof is guided into the paper guide path from the rear of a paper path which extends from the paper feeding device to the paper guide path. Moreover, a print head of the prior art printer is disposed sideward in front of the platen so as to print out on the upper surface of the printing paper which is advanced around the platen's circumference.
When a sheet of paper is inserted by hand from the insert slit of the prior printer described above, the printing paper is necessarily bent with a small radius around approximately two thirds or three quarters of the platen's circumference. Particularly, rather thick paper like a postcard is bent so hard that it is difficult to handle after being printed. In order to solve this problem, it may be possible to enlarge the platen's diameter or to shorten the range of the platen's circumference where a printing paper is rotated. However, in this case, the insert slit must be positioned apart from the platen rearward, and accordingly the paper feeding device near the insert slit must be also moved rearward, resulting in another problem, namely, enlargement of the whole printer unit.
On the other hand, when a continuous web is fed along the platen of the prior art printer, it is inserted into the paper guide path from the rear of the paper path, extending from the paper feeding device, to the paper guide path. As a result, the front edge of the sheet advances across the paper path and sometimes hits the platen's circumference, resulting in paper clogging. In order to solve this problem, the printer has to be equipped with a special device, such as the invention of U.S. Patent application No. 799, 753 made by the same inventor as this present application and filed on Nov. 19, 1985 now U.S. Pat. No. 4,802,780, issued on Feb. 7, 1989.
Another problem occurs with regards to page order of the individual cut type printed sheets. To elaborate, since the printed sheets with their upper surfaces printed by the print head are discharged and piled up one after another on the paper tray in the rear of the platen, the operator has to rearrange all the pages backward after printing is completed.
Still another problem occurs as concerning a method for discharging the continuous web. On condition that the continuous web is discharged to be piled up in the same direction as the individual cut form sheets are, it requires a space large enough for stacking the printed paper of both types. Some improvement has been made so as to solve this disadvantage in such a manner that the discharge direction of the continuous web is reversed at the outlet so as to discharge the paper to pass over the printer and to fold it under the paper which is already folded in order to be fed into the printer. However, there exist still another problems in spite of the improvement, that is: since the prior art printer is not equipped with a special paper guide at the outlet in order to discharge the printed continuous web smoothly, the web may get loose at the outlet, which interrupts the smooth paper discharge; and furthermore, since the printing paper which will be printed and the printing paper which has been already printed are piled on the same table as the printer, it is difficult for the operator to handle those different kinds of paper.